I got this backpack a few days ago. You need to collect 15000 trust points to exchange the backpack with Npc Tik'hi Tak'he.

Tasks to earn points:
1. Memory Test = 50 points / Cooldown = 2 hours
2. Supply Mission = 200 points / Cooldown = 20 hours
3. Stealth Mission = 200 points / Cooldown = 20 hours